In a report that should come as no surprise to anyone in the MMOG industry, Nielsen Media Research issued their top media results from 2008, and (you guessed it) World of Warcraft was the resounding winner in the PC gaming category by absolutely crushing all other contenders for the crown. Runescape did make the list at #6, but the fact remains that WoW is the king and will continue to hold its crown for sometime. Here's the official breakdown from Nielsen:

1. World of Warcraft (Blizzard) - 671 minutes per week (0.723% of gamers)